Hey i ordered the JBL601.1 from this one website and they said the new upgraded model was a JBL 7001. I have a link on ebay to what it looks liek and specs, i was wondering if it would work just as good for the two JBLGT5-12's i have.
Thanks for your time.
Replies (21)
swez on 07/11/2008 15:19:47
The JBL GT5-12 is rated at 275 Wrms per sub. These are 4 ohm SVC subs and pretty efficient as well.
The 600.1 has sufficient power and some reserve for these subs in a sealed box system. We have discussed this at length for SQL performance. An extra 100 watts of RMS power is not a big issue. (Especially if the cost of the amp is more that $50.00 over the 600.1)
Neither amp has SSF or IFS filters. They are not well suited to ported designs unless you use outboard SSF filters.
In a nutshell, either amp will do a fine job for sealed sub apps. Look at the price and warranty as the bottom line. Other than that, I don't see any real advantages you can hear.
Swez
SQLThump on 07/11/2008 15:43:51
Dude, with the rep on the older GTO series, get the 700.1. If you ever decide to get beefier subs, this amp will dish it out for them too. I am saving coin for one myself right now, unless I act afool and score myself the 1400.1. I am known to act afool........
Zach1989 on 07/11/2008 17:14:41
Alright thank you guys the 700.1 is only 11 dollars more than the 600.1, I wasn't sure because the 600.1 said it was a class d and i think the 700.1 is a class a/b wasn't sure if it made a difference.
I guess i will go ahead and get the 700.1 unless the class d vs. class a/b changes things a bit. Unless i read the information wrong, could be....
LOL @ the 1400.1 now that is the definition of acting a fool haha, if my car could hold up with the power i would have my backseats ripped out and have like 4 12's in that beast.
but all in due time right, If anything changes let me know if not i will plan on ordering the 700.1 on Monday because i had the 600.1 ordered and they said they switched to the 700.1 a couple months ago.
They said for the extra 11 dollars they could hook me up with one but they are closed for the weekend so i will have to pay them Monday haha.
SQLThump on 07/11/2008 18:27:09
Both amps are class D. If it's only $11 more, I'd have to shank ya for getting the 601.1 GRIN
Considering the 1400.1 and another pair of 12's. Main issue is figuring out how to rear fire al 4 of them in ported enclosures.....Screw if it can take the power or not......act afool!
and for the record.........4 12's are so much more comfortable than any back seat..........dont ask how......just believe.......
I tell you this though, these GT5-12's are so killer, I am waiting for the day I find a body in my trunk, and a JBL sub holding a bloody knife
swez on 07/12/2008 00:32:12
Let's clarify something here fellas... There is very little audible power difference between 600 & 700 watts output values. (<1dB)
If one is a DB Dragger, that might be of interest in a given classification, but in terms of actual music/bass output to the average listener, no audible benefits what so ever.
FYI: In general terms, if we double the power to a given woofer, we get a +3dB bump in SPL. When using 2 subs and we double the power to each sub, that's about +6dB more bass + transfer functions from the vehicle used.
That's how it works as audio is measured on a log scale and not a linear one. Hope that clarifies the matter.
Swez
Zach1989 on 07/12/2008 05:23:49
yea thanks a bunch swez I wasnt sure about all that, i thought maybe they would be trying to pull a fast one on me the way they threw it at me.
But i guess it was a nice offer saying a nice upgrade for cheap. thats what ill do thanks again....
swez on 07/12/2008 07:16:50
Right... the 700.1 is a newer product, has a little more reserve power for heavy bass hits, (Transient spikes) and that's not a bad thing either. For the extra $11.00, it worth it and a good deal too.
Once you get things pulled together and working, we'll show you how to dial in your amps and get things as balanced out as possible.
Are you clear on your box building design, panel cut dimensions and how best to assemble this box?
Swez
SQLThump on 07/12/2008 07:29:53
I feel what your saying on the power difference, but this case it's not so much power it's sex appeal. The 601.1 is like that boring girl you take out when your low on funds. The 700.a is like taking out Gwen Stephani for $11 more. I'd definitely have to go with Gwen.....
swez on 07/12/2008 08:30:08
Hehe, that'e a cute one SQT! Sex appeal is in the eyes of the beholder.
A hot babe that spends big $$$'s on her clothes, hair, make-up and such are high maint and tend to be less down to earth. If you want to keep one of these, better have a phat wallet and lots of patience.
After many years of dating, the most satifying and peaceful relationships stemmed from equally paired couples that have offsetting strengths and weakness to ourselves. That applies in looks, intelligence, experiences, financially and other key factors. Sheep and Goats are direct opposites, but they can learn to get along very well in time.
Have dated a few real beauties in my day and they were great for a while. But there's also a lot of competition to fend off too. They liked the fast life and I did too, many years ago. Now prefer the quiet and simple lifestyle. (Forget the in-your-face type conflicts)
BTDT and I see no need to try that rollercoaster ride on a daily basis anymore. It's exhausting, unecessary and expensive too. It's great to just be ourselves, let our partners be themselves and work together when the tough stuff in life pops up. Cooler heads prevail and leave the drama to TV and Hollywood. I don't want/need all that "DRAMA" in my home or life. To each their own...
Just my 2 centavos,
Swez
SQLThump on 07/12/2008 08:58:06
Oh, I definitely feel that. When actually selecting a woman, i would go for the boring chick any day. Plus, I love nerdy girls.
Personality is far more important to me now. Never was much for the high monetary maintanence type, looks can be found without that, but it is rare. I prefer the "ugly duckling" type, who has no idea what a swan she has become, but dealt with "I'm not hot" issues in the past. Best way to get a fine down to earth woman.
Don't get me wrong though, that high-maint chick gets some looks and a construction worker grade whistle, but little more than that. Personally don't have the desire to spend that much dough on a chick, unless the date she expects is only $11 moreGRIN
And if I end up with a drama queen (only happened once before) that girl gets dropped to the curb with the quickness. Have enough women in my family to argue with, plus my brothers, last thing I need is any more drama.
But there is one thing that sex appeal will take over any time.....stuff for the Bucket. First time I saw a 700.1, I seriously ran my finger down that heatsink and felt more than cold metal......can't wait to get one of them toe-curlers in my ride..........
swez on 07/12/2008 12:29:07
Got it and yes, I found a seemingly "ugly duckling" initially, but she had the $$$, a great personality and smart as a whip in certain areas as well. Some of the best times I can remember in life, came from her very HOT experiences before I came along.
Well, she was just a tad older than I was and we faced many tough challenges as a team too. She came from the upper crust society and I was just a blue collar guy at the time. But after a few years of observation, formal education and general learning, she taught me a lot. (In many ways)
Eventually, I surpassed many gaps, but then took a realistic view of the future. She's single, likes it that way and work came first. Alcohol was #2 and depression set in later and she fell apart. In so many ways, she had it together. But there were a few key issues we could not bridge the gap. I finally moved on for the better. (A real life lesson was the end result)
Anyway, go ahead and drool over the JBL 700.1 if ya like. Either way, both are winners at the right price.
Swez
Zach1989 on 07/12/2008 12:30:47
LOL @ SQL and swez, we went from amps to relationships, i love this site. I feel you both on that matter i dont need no more drama in my life than there already is. I got enough debt to last me a lonnnnnnnnnng time.
The last thing i need is an expensive date, shoot i could have a date right at the house cook a nice meal and just hang out thats what i do. Thats what i would rather have, like you guys say the down to earth type.
Ones that dont HAVE to go out because they know they will get the whistle and the stare, high maintenance girls usually are the ones who do that, in my experience in this part of florida anyways.
But as SQL said for 11 dollars more gwen stefani would make a nice date so ms. stefani it is. I cant wait to hear this system complete the subs are on the way i get paid thursday and will buy the box materials then.
But yeah swez, i understand form the other post the measurements spacing and arrangements, is there anyway i could get a picture of my trunk to one of yall so you can see the wedge design id have to do?
would i just upload it to a website and put the link in the post? Because in my case the wedge design would be backwords, as in the slant and h2 would be in the back of the trunk and h1 would be at the middle, do you kinda understand what im saying?
In other words the flat part of the wedge would be where id have to mount the subs leaving the "wedge" to be able to slip into the back part of the trunk.
Also, what type of sealing should i use? Screw the box together and use wood glue or is there a special glue for the audio boxes? Ohh another thing people told me to put cotton in the chambers, any comments on that?
swez on 07/12/2008 18:43:09
Hehe, when things get slow on the site, we've been known to open up a lot of OT thoughts on most any subject. Sorry we hijacked yours... LOL
Try to make the box so you can try several loactions in the trunk for the best sound. That may mean a less wider box and a deeper one to compensate. That way you have room to experiment.
As for glue, any good carpenter's glue will work. (Elmer's Pro is fine) Use enough glue so that when you sink your screws, the glue seeps and can be wiped clean with a damp paper towel. The glue is what makes the joints stay tight. The screws only hold the panels in place until the glue cures.
To seal the inner joints, use RTV Silicone with a ~1/4" bead to seal all internal joints. Just let it cure overnight before installing your subs. You know it's cured when the solvent smell is gone.
As for screws, a lb of #8 x 2" drywall screws would be fine. Just be sure to pilot drill all holes so you don't crack/split a panel. Also, use a counter sink bit to flush the heads. If there are dimples after the heads are sunk, drywall patch them and sand flat before covering the box as you wish.
As for stuffing the inner chambers, yes... there are several materials one can use to dampen the rear bass waves off the rear off the cone.
1. Loose polyfil for pillows and quilts can be had at Walmart in the sewing section. (~1 lb/chamber) They come in 1 lb bags.
2. Sheet type polyfil is fine too. (Quilt making sheets, cut to size are fine)
3. Clean carpet backing works pretty well too. (3/4"-1.0" thick) Dirt/grit free and you can get this free on rubbish night patrol.
4. A good Arrow staple gun and 14-16mm staples will do the job holding the fill material in place. Just make sure you get a good bite in MDF with your staples. If they don't seat tight, a small hammer will take care of that. If that fails, remove the lame one and shoot again.
Does that cover all your questions?
Swez
SQLThump on 07/12/2008 18:57:43
Yeah, leave us alone on your thread, instant OT hijack. Thats the rule.......
Swez, do you really think any sort of lining is neccessary here? Generelly, isn't that just for fooling subs into behaving like their in a larger enclosure, or eliminating standing waves in ported enclosures? Niether should be a problem at all with this design.....
swez on 07/13/2008 02:29:58
If you look at JBL's sub manuals, they recommend fill material in sealed enclosures to reduce standing waves inside the box.
I dunno, after building many boxes over the years for a wide variety of applications, it's become a habit I just don't question anymore. Also, all of the ceiling mounted speakers, (Metal cyliners for commercial and retail) we have installed the past few years, they all used absorbant materials inside too. (Ported & sealed) There's a good reason for that added step/cost or they would not bother.
Have a suggestion though... do some research and see what you find out as common practices like this one for speaker enclosure building from top name Hi-Fi, HT and Pro box designers. It may take some digging, but when you find out why many/most use fill, write your first DIY article for CK.
What do you think?
Swez
Zach1989 on 07/13/2008 18:20:37
Alright guys that works for me hopefully thursday I will have the materials and over the weekend i can sink my hands into it. I will do some research tomorrow morning and see what I can't come up with.
LOL its all good about the hijacking, a little comparison goes a long way. And you also get a little bit of life lessons and reason within, its a good practice.
Kinda like putting your mind on a different subject for a short break then returning to the heavy dense material you gotta cover for a good install. I do have one quick question, kinda random actually.
My Kenwood Excelon when plugged into the harness heats up rather quickly, but only in one little section, sort of like it was the "heat Absobant" part of the HU.
It is a piece of square 2" X 2" metal that covers the back middle of the unit, i was curious as if this was a problem or if it is more like a new design to keep the unit cool and "dissipate" the heat through that instead of the whole unit warming up.
Maybe acting aqs a protect of the interior circuitry?
Any Ideas?
swez on 07/14/2008 00:42:28
Yep, OT's break the ice and give some a chance to open up and share experiences that we all face from time to time. It also shifts thoughts from the usual topics and a break until work comes in again.
HU heating is normal where the internal amps are located. There's a small bank of power transistors inside the HU that are mounted to a heat sink and that helps keep the transistor from getting too hot at high volume levels. If the metal is more like a billet of milled aluminum with cooling fins, that's the heat sink.
Also, many of the better quality HU's have a feature in the menu that allows one to turn off the internal amps and just use RCA, (line level) preamps to feed only external amps.
Talked at length with my brother last night, (while fishing) about the use of sound damping materials in woofer enclosures. He's been building custom enclosures for all kinds of applications for many years. (Mostly Pro audio, live sound and stage monitors) He also swaps blown drivers as needed when the DJ's get carried away.
The general concenses here, using dampening materials helps reduce standing wave problems, (Standing waves and reflections) inside the woofer enclosure. It absorbs the rear waves radiating from the back of the cone so we get tight, well controlled bass from the enclosure design. He's used mostly fiberglass insulation in the past, but has now switched to polyfil to eliminate the "itch factor".
Hope that helps,
Swez
Zach1989 on 07/14/2008 13:07:39
Alright thats sounds good, was just curious about everything. Will keep you all posted on my progress, thanks.
Ash on 07/14/2008 21:47:31
It is always good to use some sort of fill. There are several materials and different techniques that can be applied for a greater or lesser effect.
The main reason for its use is to reduce internal resonance modes that can reflect back into the cone and obviously cause some anomalies in the speakers response. It can affect the speakers overall output when heavily applied so that's why there's usually only a minimal amount needed when the enclosure is right on spec.
Heavily stuffed when the box is on the smaller side only helps so much with it's results no greater than 10-30% depending on technique. So it should not be used to make up for a misaligned box, just more or less a tuning aid.
How this works is called isothermal. Some of the internal energy is disappated as a low level heat which in short causes the sub to work less harder against the pressure of the box, thus making it "appear" larger.
Still a fine line to this as overstuffing the box can reverse the effect and "decrease" the box size. So technique is important but not something that is totally hit or miss.
Also in ported/vented enclosures, since the obvious tuning will be changed somewhat, the port length have to be as well to keep the response flat. Not by much, but in most cases it will have to be slightly retuned.
Ash
Zach1989 on 07/16/2008 16:54:11
wow, thanks ash, that is really great information to carry on. I still am not quite sure about what I am going to do first step is to buy materials, which should be tomorrow then i can work from there.
I am going to get the mdf and make the box then carpet the outside and when i get the amp and sub see what goes on, more than likely i will buy the pillow fill that swez talked about.....
Ash on 07/16/2008 21:17:04
The pillow fill works great and is what I use in all my boxes. Just be careful not to overstuff the box or have the fill too close behind the speaker. Leave a sort of buffer area around the subs' basket & the fill so it won't suffer from frictional losses.
Thanks for your time.
Replies (21)
swez on 07/11/2008 15:19:47
The JBL GT5-12 is rated at 275 Wrms per sub. These are 4 ohm SVC subs and pretty efficient as well.
The 600.1 has sufficient power and some reserve for these subs in a sealed box system. We have discussed this at length for SQL performance. An extra 100 watts of RMS power is not a big issue. (Especially if the cost of the amp is more that $50.00 over the 600.1)
Neither amp has SSF or IFS filters. They are not well suited to ported designs unless you use outboard SSF filters.
In a nutshell, either amp will do a fine job for sealed sub apps. Look at the price and warranty as the bottom line. Other than that, I don't see any real advantages you can hear.
Swez
SQLThump on 07/11/2008 15:43:51
Dude, with the rep on the older GTO series, get the 700.1. If you ever decide to get beefier subs, this amp will dish it out for them too. I am saving coin for one myself right now, unless I act afool and score myself the 1400.1. I am known to act afool........
Zach1989 on 07/11/2008 17:14:41
Alright thank you guys the 700.1 is only 11 dollars more than the 600.1, I wasn't sure because the 600.1 said it was a class d and i think the 700.1 is a class a/b wasn't sure if it made a difference.
I guess i will go ahead and get the 700.1 unless the class d vs. class a/b changes things a bit. Unless i read the information wrong, could be....
LOL @ the 1400.1 now that is the definition of acting a fool haha, if my car could hold up with the power i would have my backseats ripped out and have like 4 12's in that beast.
but all in due time right, If anything changes let me know if not i will plan on ordering the 700.1 on Monday because i had the 600.1 ordered and they said they switched to the 700.1 a couple months ago.
They said for the extra 11 dollars they could hook me up with one but they are closed for the weekend so i will have to pay them Monday haha.
SQLThump on 07/11/2008 18:27:09
Both amps are class D. If it's only $11 more, I'd have to shank ya for getting the 601.1 GRIN
Considering the 1400.1 and another pair of 12's. Main issue is figuring out how to rear fire al 4 of them in ported enclosures.....Screw if it can take the power or not......act afool!
and for the record.........4 12's are so much more comfortable than any back seat..........dont ask how......just believe.......
I tell you this though, these GT5-12's are so killer, I am waiting for the day I find a body in my trunk, and a JBL sub holding a bloody knife
swez on 07/12/2008 00:32:12
Let's clarify something here fellas... There is very little audible power difference between 600 & 700 watts output values. (<1dB)
If one is a DB Dragger, that might be of interest in a given classification, but in terms of actual music/bass output to the average listener, no audible benefits what so ever.
FYI: In general terms, if we double the power to a given woofer, we get a +3dB bump in SPL. When using 2 subs and we double the power to each sub, that's about +6dB more bass + transfer functions from the vehicle used.
That's how it works as audio is measured on a log scale and not a linear one. Hope that clarifies the matter.
Swez
Zach1989 on 07/12/2008 05:23:49
yea thanks a bunch swez I wasnt sure about all that, i thought maybe they would be trying to pull a fast one on me the way they threw it at me.
But i guess it was a nice offer saying a nice upgrade for cheap. thats what ill do thanks again....
swez on 07/12/2008 07:16:50
Right... the 700.1 is a newer product, has a little more reserve power for heavy bass hits, (Transient spikes) and that's not a bad thing either. For the extra $11.00, it worth it and a good deal too.
Once you get things pulled together and working, we'll show you how to dial in your amps and get things as balanced out as possible.
Are you clear on your box building design, panel cut dimensions and how best to assemble this box?
Swez
SQLThump on 07/12/2008 07:29:53
I feel what your saying on the power difference, but this case it's not so much power it's sex appeal. The 601.1 is like that boring girl you take out when your low on funds. The 700.a is like taking out Gwen Stephani for $11 more. I'd definitely have to go with Gwen.....
swez on 07/12/2008 08:30:08
Hehe, that'e a cute one SQT! Sex appeal is in the eyes of the beholder.
A hot babe that spends big $$$'s on her clothes, hair, make-up and such are high maint and tend to be less down to earth. If you want to keep one of these, better have a phat wallet and lots of patience.
After many years of dating, the most satifying and peaceful relationships stemmed from equally paired couples that have offsetting strengths and weakness to ourselves. That applies in looks, intelligence, experiences, financially and other key factors. Sheep and Goats are direct opposites, but they can learn to get along very well in time.
Have dated a few real beauties in my day and they were great for a while. But there's also a lot of competition to fend off too. They liked the fast life and I did too, many years ago. Now prefer the quiet and simple lifestyle. (Forget the in-your-face type conflicts)
BTDT and I see no need to try that rollercoaster ride on a daily basis anymore. It's exhausting, unecessary and expensive too. It's great to just be ourselves, let our partners be themselves and work together when the tough stuff in life pops up. Cooler heads prevail and leave the drama to TV and Hollywood. I don't want/need all that "DRAMA" in my home or life. To each their own...
Just my 2 centavos,
Swez
SQLThump on 07/12/2008 08:58:06
Oh, I definitely feel that. When actually selecting a woman, i would go for the boring chick any day. Plus, I love nerdy girls.
Personality is far more important to me now. Never was much for the high monetary maintanence type, looks can be found without that, but it is rare. I prefer the "ugly duckling" type, who has no idea what a swan she has become, but dealt with "I'm not hot" issues in the past. Best way to get a fine down to earth woman.
Don't get me wrong though, that high-maint chick gets some looks and a construction worker grade whistle, but little more than that. Personally don't have the desire to spend that much dough on a chick, unless the date she expects is only $11 moreGRIN
And if I end up with a drama queen (only happened once before) that girl gets dropped to the curb with the quickness. Have enough women in my family to argue with, plus my brothers, last thing I need is any more drama.
But there is one thing that sex appeal will take over any time.....stuff for the Bucket. First time I saw a 700.1, I seriously ran my finger down that heatsink and felt more than cold metal......can't wait to get one of them toe-curlers in my ride..........
swez on 07/12/2008 12:29:07
Got it and yes, I found a seemingly "ugly duckling" initially, but she had the $$$, a great personality and smart as a whip in certain areas as well. Some of the best times I can remember in life, came from her very HOT experiences before I came along.
Well, she was just a tad older than I was and we faced many tough challenges as a team too. She came from the upper crust society and I was just a blue collar guy at the time. But after a few years of observation, formal education and general learning, she taught me a lot. (In many ways)
Eventually, I surpassed many gaps, but then took a realistic view of the future. She's single, likes it that way and work came first. Alcohol was #2 and depression set in later and she fell apart. In so many ways, she had it together. But there were a few key issues we could not bridge the gap. I finally moved on for the better. (A real life lesson was the end result)
Anyway, go ahead and drool over the JBL 700.1 if ya like. Either way, both are winners at the right price.
Swez
Zach1989 on 07/12/2008 12:30:47
LOL @ SQL and swez, we went from amps to relationships, i love this site. I feel you both on that matter i dont need no more drama in my life than there already is. I got enough debt to last me a lonnnnnnnnnng time.
The last thing i need is an expensive date, shoot i could have a date right at the house cook a nice meal and just hang out thats what i do. Thats what i would rather have, like you guys say the down to earth type.
Ones that dont HAVE to go out because they know they will get the whistle and the stare, high maintenance girls usually are the ones who do that, in my experience in this part of florida anyways.
But as SQL said for 11 dollars more gwen stefani would make a nice date so ms. stefani it is. I cant wait to hear this system complete the subs are on the way i get paid thursday and will buy the box materials then.
But yeah swez, i understand form the other post the measurements spacing and arrangements, is there anyway i could get a picture of my trunk to one of yall so you can see the wedge design id have to do?
would i just upload it to a website and put the link in the post? Because in my case the wedge design would be backwords, as in the slant and h2 would be in the back of the trunk and h1 would be at the middle, do you kinda understand what im saying?
In other words the flat part of the wedge would be where id have to mount the subs leaving the "wedge" to be able to slip into the back part of the trunk.
Also, what type of sealing should i use? Screw the box together and use wood glue or is there a special glue for the audio boxes? Ohh another thing people told me to put cotton in the chambers, any comments on that?
swez on 07/12/2008 18:43:09
Hehe, when things get slow on the site, we've been known to open up a lot of OT thoughts on most any subject. Sorry we hijacked yours... LOL
Try to make the box so you can try several loactions in the trunk for the best sound. That may mean a less wider box and a deeper one to compensate. That way you have room to experiment.
As for glue, any good carpenter's glue will work. (Elmer's Pro is fine) Use enough glue so that when you sink your screws, the glue seeps and can be wiped clean with a damp paper towel. The glue is what makes the joints stay tight. The screws only hold the panels in place until the glue cures.
To seal the inner joints, use RTV Silicone with a ~1/4" bead to seal all internal joints. Just let it cure overnight before installing your subs. You know it's cured when the solvent smell is gone.
As for screws, a lb of #8 x 2" drywall screws would be fine. Just be sure to pilot drill all holes so you don't crack/split a panel. Also, use a counter sink bit to flush the heads. If there are dimples after the heads are sunk, drywall patch them and sand flat before covering the box as you wish.
As for stuffing the inner chambers, yes... there are several materials one can use to dampen the rear bass waves off the rear off the cone.
1. Loose polyfil for pillows and quilts can be had at Walmart in the sewing section. (~1 lb/chamber) They come in 1 lb bags.
2. Sheet type polyfil is fine too. (Quilt making sheets, cut to size are fine)
3. Clean carpet backing works pretty well too. (3/4"-1.0" thick) Dirt/grit free and you can get this free on rubbish night patrol.
4. A good Arrow staple gun and 14-16mm staples will do the job holding the fill material in place. Just make sure you get a good bite in MDF with your staples. If they don't seat tight, a small hammer will take care of that. If that fails, remove the lame one and shoot again.
Does that cover all your questions?
Swez
SQLThump on 07/12/2008 18:57:43
Yeah, leave us alone on your thread, instant OT hijack. Thats the rule.......
Swez, do you really think any sort of lining is neccessary here? Generelly, isn't that just for fooling subs into behaving like their in a larger enclosure, or eliminating standing waves in ported enclosures? Niether should be a problem at all with this design.....
swez on 07/13/2008 02:29:58
If you look at JBL's sub manuals, they recommend fill material in sealed enclosures to reduce standing waves inside the box.
I dunno, after building many boxes over the years for a wide variety of applications, it's become a habit I just don't question anymore. Also, all of the ceiling mounted speakers, (Metal cyliners for commercial and retail) we have installed the past few years, they all used absorbant materials inside too. (Ported & sealed) There's a good reason for that added step/cost or they would not bother.
Have a suggestion though... do some research and see what you find out as common practices like this one for speaker enclosure building from top name Hi-Fi, HT and Pro box designers. It may take some digging, but when you find out why many/most use fill, write your first DIY article for CK.
What do you think?
Swez
Zach1989 on 07/13/2008 18:20:37
Alright guys that works for me hopefully thursday I will have the materials and over the weekend i can sink my hands into it. I will do some research tomorrow morning and see what I can't come up with.
LOL its all good about the hijacking, a little comparison goes a long way. And you also get a little bit of life lessons and reason within, its a good practice.
Kinda like putting your mind on a different subject for a short break then returning to the heavy dense material you gotta cover for a good install. I do have one quick question, kinda random actually.
My Kenwood Excelon when plugged into the harness heats up rather quickly, but only in one little section, sort of like it was the "heat Absobant" part of the HU.
It is a piece of square 2" X 2" metal that covers the back middle of the unit, i was curious as if this was a problem or if it is more like a new design to keep the unit cool and "dissipate" the heat through that instead of the whole unit warming up.
Maybe acting aqs a protect of the interior circuitry?
Any Ideas?
swez on 07/14/2008 00:42:28
Yep, OT's break the ice and give some a chance to open up and share experiences that we all face from time to time. It also shifts thoughts from the usual topics and a break until work comes in again.
HU heating is normal where the internal amps are located. There's a small bank of power transistors inside the HU that are mounted to a heat sink and that helps keep the transistor from getting too hot at high volume levels. If the metal is more like a billet of milled aluminum with cooling fins, that's the heat sink.
Also, many of the better quality HU's have a feature in the menu that allows one to turn off the internal amps and just use RCA, (line level) preamps to feed only external amps.
Talked at length with my brother last night, (while fishing) about the use of sound damping materials in woofer enclosures. He's been building custom enclosures for all kinds of applications for many years. (Mostly Pro audio, live sound and stage monitors) He also swaps blown drivers as needed when the DJ's get carried away.
The general concenses here, using dampening materials helps reduce standing wave problems, (Standing waves and reflections) inside the woofer enclosure. It absorbs the rear waves radiating from the back of the cone so we get tight, well controlled bass from the enclosure design. He's used mostly fiberglass insulation in the past, but has now switched to polyfil to eliminate the "itch factor".
Hope that helps,
Swez
Zach1989 on 07/14/2008 13:07:39
Alright thats sounds good, was just curious about everything. Will keep you all posted on my progress, thanks.
Ash on 07/14/2008 21:47:31
It is always good to use some sort of fill. There are several materials and different techniques that can be applied for a greater or lesser effect.
The main reason for its use is to reduce internal resonance modes that can reflect back into the cone and obviously cause some anomalies in the speakers response. It can affect the speakers overall output when heavily applied so that's why there's usually only a minimal amount needed when the enclosure is right on spec.
Heavily stuffed when the box is on the smaller side only helps so much with it's results no greater than 10-30% depending on technique. So it should not be used to make up for a misaligned box, just more or less a tuning aid.
How this works is called isothermal. Some of the internal energy is disappated as a low level heat which in short causes the sub to work less harder against the pressure of the box, thus making it "appear" larger.
Still a fine line to this as overstuffing the box can reverse the effect and "decrease" the box size. So technique is important but not something that is totally hit or miss.
Also in ported/vented enclosures, since the obvious tuning will be changed somewhat, the port length have to be as well to keep the response flat. Not by much, but in most cases it will have to be slightly retuned.
Ash
Zach1989 on 07/16/2008 16:54:11
wow, thanks ash, that is really great information to carry on. I still am not quite sure about what I am going to do first step is to buy materials, which should be tomorrow then i can work from there.
I am going to get the mdf and make the box then carpet the outside and when i get the amp and sub see what goes on, more than likely i will buy the pillow fill that swez talked about.....
Ash on 07/16/2008 21:17:04
The pillow fill works great and is what I use in all my boxes. Just be careful not to overstuff the box or have the fill too close behind the speaker. Leave a sort of buffer area around the subs' basket & the fill so it won't suffer from frictional losses.
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